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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Internal Stresses and Social Feedback Mechanisms in Social-Ecological Systems: A Multi-Method Approach to the Effectiveness of Exit and Voice

January 2020 (has links)
abstract: My research is motivated by a rule of thumb that no matter how well a system is designed, some actors fail to fulfill the behavior which is needed to sustain the system. Examples of misbehavior are shirking, rule infraction, and free riding. With a focus on social-ecological systems, this thesis explored the effectiveness of social feedback mechanisms driven by the two available individual options: the exit option is defined as any response to escape from an objectionable state of affairs; and the voice option as any attempt to stay put and improve the state. Using a stylized dynamic model, the first study investigates how the coexistence of participatory and groundwater market institutions affects government-managed irrigation systems. My findings suggest that patterns of bureaucratic reactions to exit (using private tubewells) and voice (putting pressure on irrigation bureaus) are critical to shaping system dynamics. I also found that the silence option – neither exit nor voice – can impede a further improvement in public infrastructure, but in some cases, can improve public infrastructure dramatically. Using a qualitative comparative analysis of 30 self-governing fishing groups in South Korea, the second study examines how resource mobility, group size, and Ostrom’s Design Principles for rule enforcement can co-determine the effectiveness of the voice option in self-controlling rule infractions. Results suggest that the informal mechanism for conflict resolution is a necessary condition for successful self-governance of local fisheries and that even if rules for monitoring and graduated sanctions are not in use, groups can be successful when they harvest only stationary resources. Using an agent-based model of public good provision, the third study explores under what socioeconomic conditions the exit option – neither producing nor consuming collective benefits – can work effectively to enhance levels of cooperation. The model results suggest that the exit option contributes to the spread of cooperators in mid- and large-size groups at the moderate level of exit payoff, given that group interaction occurs to increase the number of cooperators. / Dissertation/Thesis / Doctoral Dissertation Environmental Social Science 2020
2

Anthropogenic Disturbances and Shifts in Tropical Seagrass Ecosystems

Eklöf, Johan S. January 2008 (has links)
<p>Seagrasses constitute the basis for diverse and productive ecosystems worldwide. In East Africa, they provide important ecosystem services (e.g. fisheries) but are potentially threatened by increasing resource use and lack of enforced management regulations. The major aim of this PhD thesis was to investigate effects of anthropogenic distur-bances, primarily seaweed farming and coastal fishery, in East African seagrass beds. Seaweed farming, often depicted as a sustainable form of aquaculture, had short- and long-term effects on seagrass growth and abundance that cascaded up through the food web to the level of fishery catches. The coastal fishery, a major subsistence activity in the region, can by removing urchin predators indirectly increase densities of the sea urchin <i>Tripneustes gratilla</i>, which has overgrazed seagrasses in several areas. A study using simulated grazing showed that high magnitude leaf removal – typical of grazing urchins – affected seagrasses more than low magnitude removal, typical of fish grazing. Different responses in two co-occurring seagrass species furthermore indicate that high seagrass diversity in tropical seagrass beds could buffer overgrazing effects in the long run. Finally, a literature synthesis suggests that anthropogenic disturbances could drive shifts in seagrass ecosystems to an array of alternative regimes dominated by other or-ganisms (macroalgae, bivalves, burrowing shrimp, polychaetes, etc.). The formation of novel feedback mechanisms makes these regimes resilient to disturbances like seagrass recovery and transplantation projects. Overall, this suggests that resource use activities linked to seagrasses can have large-scale implications if the scale exceeds critical levels. This emphasizes the need for holistic and adaptive management at the seascape level, specifically involving improved techniques for seaweed farming and fisheries, protection of keystone species, and ecosystem-based management approaches.</p>
3

Anthropogenic Disturbances and Shifts in Tropical Seagrass Ecosystems

Eklöf, Johan S. January 2008 (has links)
Seagrasses constitute the basis for diverse and productive ecosystems worldwide. In East Africa, they provide important ecosystem services (e.g. fisheries) but are potentially threatened by increasing resource use and lack of enforced management regulations. The major aim of this PhD thesis was to investigate effects of anthropogenic distur-bances, primarily seaweed farming and coastal fishery, in East African seagrass beds. Seaweed farming, often depicted as a sustainable form of aquaculture, had short- and long-term effects on seagrass growth and abundance that cascaded up through the food web to the level of fishery catches. The coastal fishery, a major subsistence activity in the region, can by removing urchin predators indirectly increase densities of the sea urchin Tripneustes gratilla, which has overgrazed seagrasses in several areas. A study using simulated grazing showed that high magnitude leaf removal – typical of grazing urchins – affected seagrasses more than low magnitude removal, typical of fish grazing. Different responses in two co-occurring seagrass species furthermore indicate that high seagrass diversity in tropical seagrass beds could buffer overgrazing effects in the long run. Finally, a literature synthesis suggests that anthropogenic disturbances could drive shifts in seagrass ecosystems to an array of alternative regimes dominated by other or-ganisms (macroalgae, bivalves, burrowing shrimp, polychaetes, etc.). The formation of novel feedback mechanisms makes these regimes resilient to disturbances like seagrass recovery and transplantation projects. Overall, this suggests that resource use activities linked to seagrasses can have large-scale implications if the scale exceeds critical levels. This emphasizes the need for holistic and adaptive management at the seascape level, specifically involving improved techniques for seaweed farming and fisheries, protection of keystone species, and ecosystem-based management approaches.
4

The Selfless Constitution : experimentation&flourishing as the foundations of South Africa's basic law

Woolman, Stu (Stuart Craig) 25 August 2008 (has links)
The way the vast majority of us think about the self, consciousness and free will is incorrect – dramatically out of step with what the majority of neuroscientists, cognitive psychologists scientists and analytic philosophers have to say about those subjects. One consequence of these erroneous views is that the manner in which the majority of us understand ‘freedom’ – as a metaphysical term and as a political concept -- is sharply at odds with how things actually are. We replicate similar kinds of errors when we think about how various forms of human association are constructed and how change actually occurs within such associations. Once again, epistemological fallacies with regard to social theory have the consequence of leading us to attribute far greater ‘freedom’ to groups than they actually possess. This second misattribution of autonomy results in institutional political arrangements and constitutional doctrines at odds with what we know about the human condition. As things stand, the various models of political theory with which the South African Constitutional Court operates rest upon a belief that the rights and freedoms enshrined in the Final Constitution should enable individuals to exercise relatively unfettered control over decisions about the intimate relationships and the various practices deemed critical to their self-understanding. However, individual autonomy as a foundation for constitutional theory overemphasizes dramatically the actual space for self-defining choices. In truth, our experience of personhood, of self-consciousness, is a function of a complex set of narratives over which we exercise little in the way of (self) control. The involuntary and arational nature of identity formation – at the level of both the individual and the social -- requires a constitutional theory that supplants the model of a rational individual moral agent which undergirds much of our current jurisprudence with a vision of the self that is more appropriately located within and determined by the associations to which we all belong. Despite the involuntary and arational nature of identity formation, we can live within communities that determine the greater part of the meaning we make, and still remain committed to the possibility of significant change (for the better) within those communities. This thesis then goes on to explain how a commitment to experimentalism in the political domain, when married to a robust conception of basic entitlements and citizenship, services human flourishing. (To expand the conditions for flourishing, however, is not to make us metaphysically ‘free’ to ‘will’ our actions: a commitment to flourishing reflects an attempt to create an environment in which all inhabitants of South Africa have the opportunity to live lives worth valuing.) Experimental constitutionalism dovetails with a very modest, naturalized account of flourishing because both accounts (1) take the radical givenness of existing constitutive attachments seriously; (2) recognize the boundedness of individual and collective rationality; and (3) describe various kinds of feedback mechanisms that allow for error correction and the enhancement of the conditions of being. Experimental constitutionalism, in particular, enables more citizens to see what ‘works’ and what doesn’t – both with respect to the means and the ends of our existence. Experimental constitutionalism offers the promise of improving the conditions for being by suggesting a range of alterations in constitutional doctrine and a host of changes in the manner in which many political institutions operate. In South Africa, the innovations associated with experimental constitutional design embrace: (1) a doctrine of constitutional supremacy that maintains a meaningful equilibrium with a doctrine of separation of powers, and thus sets relatively clear guidelines for how authority for constitutional interpretation might best be shared by the judiciary, the legislature, the executive and non-state-actors; (2) the use of various standard judicial mechanisms – such as cost orders, court procedures, amici and intervenors, expanded constitutional jurisdiction and structural injunctions – to create bubbles of participatory democracy better able (than courts or legislatures) to resolve various kinds of polycentric conflict; (3) an approach to limitations analysis that provides a better process than ‘balancing’ for experimentalist adjudication; and (4) greater roles for Chapter 9 Institutions with respect to investigation, information-sharing and norm-setting; and (5) a principle of democracy that invites public participation in law-making that will both elicit better information about which government policies work best and effect widespread reflection about the meaning of those constitutional norms that govern our lives. The thesis then (a) mines the brief historical record of two important policy areas – Housing and Education – to show how the principles of experimental constitutionalism have already been put to work and (b) re-examines six Constitutional Court cases to demonstrate how the dual commitment to experimental constitutionalism and flourishing might generate more optimal outcomes. / Thesis (LLD)--University of Pretoria, 2008. / Public Law / unrestricted

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